American Black Duck vs Blue Duck
Anas rubripes 比較対象 Hymenolaimus malacorhynchos
Side-by-Side Comparison
| 属性 | American Black Duck | Blue Duck |
|---|---|---|
| 学名 | Anas rubripes | Hymenolaimus malacorhynchos |
| 目 | Anseriformes | Anseriformes |
| 科 | Anatidae | Anatidae |
| 保全状況 | Least Concern | Endangered |
| 体長 | — | — |
| 翼開長 | 53.4 cm (21.0 in) | 45.6 cm (18.0 in) |
| 体重 | 1211.25 g (42.73 oz) | 861.75 g (30.40 oz) |
| 食性 | Eats fish and aquatic invertebrates; dives in coastal and freshwater habitats; diet shifts toward molluscs … | Eats aquatic invertebrates, seeds, and plant material; dabbles in shallow fresh water; invertebrate diet peaks … |
| 一腹卵数 | 1-17 | 5-6 |
| Population Trend | — | — |
Habitat Comparison
American Black Duck
Freshwater and brackish wetlands in eastern North America from Atlantic Canada south along the coast to Georgia. Breeds in northern bogs and wetlands. Winters on coastal marshes, estuaries, and freshwater lakes.
Blue Duck
Fast-flowing clear turbulent mountain rivers and streams in pristine native forest at 300–1,500 m in both main islands of New Zealand. Requires undisturbed riparian habitat with abundant aquatic invertebrates.
Song & Call Comparison
American Black Duck
Female produces a loud, deep quacking series; male gives a low, raspy grunt. Voice is deeper and huskier than a Mallard; pairs call powerfully across northeastern North American wetlands.
Blue Duck
A soft, musical whistle from fast-flowing South Island rivers. Call is a clear 'whio' — giving the bird its Maori name. Also gives a soft, reedy 'squeak'. Endangered; rarely heard.
Geographic Range & Migration
American Black Duck
Breeds in the steppe zone of Central Asia; winters in South Asia, East Africa, and coastal Southeast Asia.
Blue Duck
Breeds on open prairie wetlands of the Great Plains; winters in shallow estuaries and marshes along the Gulf of Mexico.
保全状況
American Black Duck
Blue Duck
How to Tell Them Apart
American Black Duck
Sooty dark brown body; head and neck paler buff with dark streaking. Iridescent purple speculum without white border. Males have yellow-green bill; females olive with orange blotches. Silvery underwings in …
Blue Duck
Distinctive slate-blue-gray plumage; breast spotted with chestnut-brown in both sexes. Pale bill with flexible pink lobes at tip. Chestnut eye. Sexes similar; adapted to fast-flowing mountain streams in New Zealand.
About These Birds
American Black Duck
北米東部の湿地、沼、河川に生息するカモ（体長53〜61cm）。全体的に暗褐色でマガモの雌に似るが、嘴の色や翼鏡の色が異なる。Anas rubripes（アメリカクロガモ）は海岸の塩性湿地から内陸の淡水域まで幅広く利用し、マガモとの雑種が多く観察される。Anatidae科。
Blue Duck
ブルーダックはニュージーランド固有の希少なカモで、ニュージーランドの国鳥の候補の一つです。青灰色の羽毛と岩の間を縫うように飛ぶ能力が特徴的です。急流の清澄な渓流に生息し、水生昆虫を主食とします。